All words are structured starting with a root, and some are accompanied by prefixes and suffixes. It is far easier to understand the meaning of a word once the word is broken down as to its root, prefix and suffix.
Roots are the main part of the word. For example, in the word bicycle, "cycle" is the root. The word can be accompanied by many prefixes including "re" or "bi." The key is to find the part of the word that can stand alone, and in "bicycle" that word is "cycle." The root of the word, much like a plant, is the most important part because it defines the word.
Prefixes reside before the root word. In the word "bicycle," "bi" is the prefix. The placement of the prefix is easy to remember because "pre" means "before." Prefixes can change the meaning of the word but can't change the basic understanding of the root. "Cycle" will always mean the same thing, but "bi" defines it as having two wheels.
A suffix is located behind the root of a word. The suffix is always located at the end of a word and can change the tense between present and past, as in the word "reacted," whose suffix "ed" makes the word past tense. The suffix can also change the word's part of speech. In the word "reliable," the root word "rely" is a verb; the suffix "able" makes the word an adjective.
Not all words consist of a root, prefix and suffix. Prefixes and suffixes are known as "affixes" because they attach to the root of a word. An understanding of all the different prefixes and suffixes is essential to understanding words.